Newish build warning:
{
content/base/src/nsObjectLoadingContent.cpp: In member function ‘bool nsObjectLoadingContent::ShouldPlay(nsObjectLoadingContent::FallbackType&)’:
content/base/src/nsObjectLoadingContent.cpp:2501:11: warning: unused variable ‘topUri’ [-Wunused-variable]
}
This variable was never unused in the changeset that added it (for bug 745030):
https://hg.mozilla.org/mozilla-central/rev/615a657305b5#l1.1453
Presumably, that line can just be removed.